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[PATCH] Initialize __x86_shared_non_temporal_threshold only if zero
- From: "H.J. Lu" <hjl dot tools at gmail dot com>
- To: GNU C Library <libc-alpha at sourceware dot org>
- Date: Sun, 8 May 2016 08:57:28 -0700
- Subject: [PATCH] Initialize __x86_shared_non_temporal_threshold only if zero
- Authentication-results: sourceware.org; auth=none
Support setting processor-specific __x86_shared_non_temporal_threshold
value in init_cpu_features.
Tested on x86 and x86-64. Any comments and feebacks?
H.J.
---
* sysdeps/x86/cacheinfo.c (__x86_shared_non_temporal_threshold):
Initialize only if it is zero.
---
sysdeps/x86/cacheinfo.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/sysdeps/x86/cacheinfo.c b/sysdeps/x86/cacheinfo.c
index 143b333..788f42d 100644
--- a/sysdeps/x86/cacheinfo.c
+++ b/sysdeps/x86/cacheinfo.c
@@ -669,5 +669,6 @@ init_cacheinfo (void)
/* The large memcpy micro benchmark in glibc shows that 6 times of
shared cache size is the approximate value above which non-temporal
store becomes faster. */
- __x86_shared_non_temporal_threshold = __x86_shared_cache_size * 6;
+ if (__x86_shared_non_temporal_threshold == 0)
+ __x86_shared_non_temporal_threshold = __x86_shared_cache_size * 6;
}
--
2.5.5